/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file sprite.h Base for drawing complex sprites. */

#ifndef SPRITE_H
#define SPRITE_H

#include "transparency.h"

#include "table/sprites.h"

#define GENERAL_SPRITE_COLOUR(colour) ((colour) + PALETTE_RECOLOUR_START)
#define COMPANY_SPRITE_COLOUR(owner) (GENERAL_SPRITE_COLOUR(_company_colours[owner]))

/* The following describes bunch of sprites to be drawn together in a single 3D
 * bounding box. Used especially for various multi-sprite buildings (like
 * depots or stations): */

/** A tile child sprite and palette to draw for stations etc, with 3D bounding box */
struct DrawTileSeqStruct {
	int8_t delta_x = 0;
	int8_t delta_y = 0;
	int8_t delta_z = 0; ///< \c 0x80 identifies child sprites
	uint8_t size_x = 0;
	uint8_t size_y = 0;
	uint8_t size_z = 0;
	PalSpriteID image{};

	/** Check whether this is a parent sprite with a boundingbox. */
	bool IsParentSprite() const
	{
		return (uint8_t)this->delta_z != 0x80;
	}
};

/**
 * Ground palette sprite of a tile, together with its sprite layout.
 * For static sprite layouts see #DrawTileSpriteSpan.
 * For allocated ones from NewGRF see #NewGRFSpriteLayout.
 */
struct DrawTileSprites {
	PalSpriteID ground{}; ///< Palette and sprite for the ground

	DrawTileSprites(PalSpriteID ground) : ground(ground) {}
	DrawTileSprites() = default;

	virtual ~DrawTileSprites() = default;
	virtual std::span<const DrawTileSeqStruct> GetSequence() const = 0;
};

/**
 * Ground palette sprite of a tile, together with its sprite layout.
 * This struct is used for static sprite layouts in the code.
 * For allocated ones from NewGRF see #NewGRFSpriteLayout.
 */
struct DrawTileSpriteSpan : DrawTileSprites {
	std::span<const DrawTileSeqStruct> seq; ///< Child sprites,

	template <size_t N>
	DrawTileSpriteSpan(PalSpriteID ground, const DrawTileSeqStruct (&seq)[N]) : DrawTileSprites(ground), seq(std::begin(seq), std::end(seq)) {}
	DrawTileSpriteSpan(PalSpriteID ground) : DrawTileSprites(ground) {};
	DrawTileSpriteSpan() = default;

	std::span<const DrawTileSeqStruct> GetSequence() const override { return this->seq; }
};

/**
 * This structure is the same for both Industries and Houses.
 * Buildings here reference a general type of construction
 */
struct DrawBuildingsTileStruct {
	PalSpriteID ground;
	PalSpriteID building;
	uint8_t subtile_x;
	uint8_t subtile_y;
	uint8_t width;
	uint8_t height;
	uint8_t dz;
	uint8_t draw_proc;  // this allows to specify a special drawing procedure.
};

void DrawCommonTileSeq(const struct TileInfo *ti, const DrawTileSprites *dts, TransparencyOption to, int32_t orig_offset, uint32_t newgrf_offset, PaletteID default_palette, bool child_offset_is_unsigned);
void DrawCommonTileSeqInGUI(int x, int y, const DrawTileSprites *dts, int32_t orig_offset, uint32_t newgrf_offset, PaletteID default_palette, bool child_offset_is_unsigned);

/**
 * Draw tile sprite sequence on tile with railroad specifics.
 * @param total_offset Spriteoffset from normal rail to current railtype.
 * @param newgrf_offset Startsprite of the Action1 to use.
 */
inline void DrawRailTileSeq(const struct TileInfo *ti, const DrawTileSprites *dts, TransparencyOption to, int32_t total_offset, uint32_t newgrf_offset, PaletteID default_palette)
{
	DrawCommonTileSeq(ti, dts, to, total_offset, newgrf_offset, default_palette, false);
}

/**
 * Draw tile sprite sequence in GUI with railroad specifics.
 * @param total_offset Spriteoffset from normal rail to current railtype.
 * @param newgrf_offset Startsprite of the Action1 to use.
 */
inline void DrawRailTileSeqInGUI(int x, int y, const DrawTileSprites *dts, int32_t total_offset, uint32_t newgrf_offset, PaletteID default_palette)
{
	DrawCommonTileSeqInGUI(x, y, dts, total_offset, newgrf_offset, default_palette, false);
}

/**
 * Draw TTD sprite sequence on tile.
 */
inline void DrawOrigTileSeq(const struct TileInfo *ti, const DrawTileSprites *dts, TransparencyOption to, PaletteID default_palette)
{
	DrawCommonTileSeq(ti, dts, to, 0, 0, default_palette, false);
}

/**
 * Draw TTD sprite sequence in GUI.
 */
inline void DrawOrigTileSeqInGUI(int x, int y, const DrawTileSprites *dts, PaletteID default_palette)
{
	DrawCommonTileSeqInGUI(x, y, dts, 0, 0, default_palette, false);
}

/**
 * Draw NewGRF industrytile or house sprite layout
 * @param stage Sprite inside the Action1 spritesets to use, i.e. construction stage.
 */
inline void DrawNewGRFTileSeq(const struct TileInfo *ti, const DrawTileSprites *dts, TransparencyOption to, uint32_t stage, PaletteID default_palette)
{
	DrawCommonTileSeq(ti, dts, to, 0, stage, default_palette, true);
}

/**
 * Draw NewGRF object in GUI
 * @param stage Sprite inside the Action1 spritesets to use, i.e. construction stage.
 */
inline void DrawNewGRFTileSeqInGUI(int x, int y, const DrawTileSprites *dts, uint32_t stage, PaletteID default_palette)
{
	DrawCommonTileSeqInGUI(x, y, dts, 0, stage, default_palette, true);
}

/**
 * Applies PALETTE_MODIFIER_TRANSPARENT and PALETTE_MODIFIER_COLOUR to a palette entry of a sprite layout entry
 * @note for ground sprites use #GroundSpritePaletteTransform
 * @note Not usable for OTTD internal spritelayouts from table/xxx_land.h as PALETTE_MODIFIER_TRANSPARENT is only set
 *       when to use the default palette.
 *
 * @param image The sprite to draw
 * @param pal The palette from the sprite layout
 * @param default_pal The default recolour sprite to use (typically company colour resp. random industry/house colour)
 * @return The palette to use
 */
inline PaletteID SpriteLayoutPaletteTransform(SpriteID image, PaletteID pal, PaletteID default_pal)
{
	if (HasBit(image, PALETTE_MODIFIER_TRANSPARENT) || HasBit(image, PALETTE_MODIFIER_COLOUR)) {
		return (pal != 0 ? pal : default_pal);
	} else {
		return PAL_NONE;
	}
}

/**
 * Applies PALETTE_MODIFIER_COLOUR to a palette entry of a ground sprite
 * @note Not usable for OTTD internal spritelayouts from table/xxx_land.h as PALETTE_MODIFIER_TRANSPARENT is only set
 *       when to use the default palette.
 *
 * @param image The sprite to draw
 * @param pal The palette from the sprite layout
 * @param default_pal The default recolour sprite to use (typically company colour resp. random industry/house colour)
 * @return The palette to use
 */
inline PaletteID GroundSpritePaletteTransform(SpriteID image, PaletteID pal, PaletteID default_pal)
{
	if (HasBit(image, PALETTE_MODIFIER_COLOUR)) {
		return (pal != 0 ? pal : default_pal);
	} else {
		return PAL_NONE;
	}
}

#endif /* SPRITE_H */